The Emir of Cordoba built the Arab wall and Alcazar in Madrid in 865 next to a creek that led to the Manzanares River. It was located in an area inhabited by both Arabs and Christians during the Middle Ages, and included important streets like Plaza del Alamillo. The structures were built to alert of Christian incursions from northern Iberia and protect Toledo. Remains of the Arab wall were found under the palace of Malpica, consisting of stone and adobe bricks with Cordoban towers.